Process of manufacture of composite bearings and other composite machine parts



May 22, 1951 v F. E. BURGER 2,

PROCESS OF MANUFACTURE OF COMPOSITE BEARINGS AND OTHER COMPOSITE MACHINEPARTS Filed Sept. 19, 1945 4 Sheets-Sheet 1 Z/Yl/eNTAR 5 a m Ma May 22,1951 F. E. BURGER 2,554,008

PROCESS OF MANUFACTURE OF COMPOSITE BEARINGS AND OTHER COMPQSITE MACHINEPARTS Filed Sept. 19, 1945 v 4 Sheets-Sheet 2 May 22, 1951 2,554,008

F. E. BURGER PROCESS OF MANUFACTURE OF COMPOSITE BEARINGS AND OTHERCOMPOSITE MACHINE PARTS Filed Sept. 19, 1945 4 Sheets-Sheet 5 i 5Q s:

2? 6 E k\\\\\\ \\\\\N May 22 1951 2,554,008

' F. E. BURGER PROCESS MANUFACTURE OF COMP TE BEARINGS AN THER COMPOSITEMACH PARTS v Filed Sept. 19, 1945 I 4 Sheets-Sheet 4 II II II 1 11 17 IIII I ll! EY MM$ Patented May 22, 1951 UNITED STAT COMPOSITE BEARINGS ANDOTHER COIW POSITE V CHINE PARTS Frank Edward Burger, Warren Row, nearRead- 7 ing, England, assigno r to J aru Limited, England, a Britishcompany Application September 19, 1945, Serial No. 617,297

In Great Britain September 29, 1944 i This invention comprisesimprovements in or relating to processes of manufacture of compositebearings and other composite machine-parts.

In United States Patent Specification No, 571,045 there is. described acomposite bearing in which a number of separate bearing surfacejelementsare assembled close together in or on a supporting body of resilientmaterial which serves to support the elements and space them from eachother, thereby enabling them to yield so as to substantially conform tochanges of shapeor size of the mechanical part with which the bearingco-operates. The present invention relates .to

a method of manufacture of such bearings and of other compositemachine-parts, such for example as oil seals, composite sleeves for muffcouplings and the like. In all these cases a number of separate elementsare arranged to be supported 3 Claims. (91. 29149.5)

close together on a supporting body of resilient material whichconstitutes the means whereby the elements are maintained in positionand by which stresses are transmitted to other parts of the apparatus inconnection with which the hearing or like machine-part is employed.

According tothe present invention a method of manufacture of compositebearings or other composite machine-parts of the kind described,consists in first forming the elements of themachine-part, which are tobe supported on the resilient material, with extensions which may act astemporary holding vmeans, mechanically holding them in relation to oneanother by means of the temporary holding means in the position whichthey are intended to occupy in the finished machine-part, while they areso held forcing mouldable resilient material in plastic condition intocontact with the elements, maintaining the Whole under heat and pressureuntil the mouldable resilient material has become bonded to the elementsand thereafter machining away the temporary holding means.

Conveniently the temporary holding means are provided by initiallyforming the elements as part of a single member which comprises theholding means and the elements, and after the bonding operation thetemporary holding means is machined away so as to separate the elementsfrom one another. 7 1

The following is a description byway oi example of certain specificinstances of'the manufacture of machine-parts lina'ccordance with thepresent invention: r f ,j V In the accompanying' drawingsz Figurel is aplanet abearing liner; j Figure 2 is a section pon the line 2 2 of Fig;-

ure 1, looking in the. direction of the arrows Figure 3 is an outsideelevation of apart which includes bearing pads for the liner shownfinFigure 1; l.

Figure 4 is a yertical section through a mould; Figure 5 is alongitudinal section through a bearing liner as it comes from the mouldof a Figure 4 and before machining to the form shown inFigures1and2;'

Figure fiisalongitudinal section; Figure 7 is a plan of a split bearingliner;v Figure 8 is a view ofjbeari'ng pads in the bearing of Figures 6andtemporarily united together by a temporary holdingportion;

Figure 9 is a longit 'dinal section through a mould showing the mouldingoperation; I j Figure 10 is a longitudinal section through a completedbearing pr'iorto removal of the temporary holding portion;

Figurellisaplan; Figure 12 is a longitudinal section through an oilsealingring;v r J Figure 13 is a longitudinal section through'anassembly of bearing pads formed upon a temporary supporting member; I

Figure 14 is a longitudinal section, partly in perspective, through anoutside supporting ring, forming part of the oil seal, showing temporaryholding means therefor;

Figure 15 is a longitudinal-section througha mould,and Figure 16 shows amanufactured part comprising a numberof oil sealing rings after ejectionfrom the mould and prior to parting off to 'produce the oil sealing ringof Figures 11 and1l2. Referring to Figures '1 and-2, these showirabearing liner which consists of a flexible-outer steel ring II and anumber of separate Phosphor bronze bearing pads I2 which are locatedwithin the ring I I and are spaced therefrom, and

.from one another, by a'supporting body of resilthey arecorrectlyt'spaced. fromoneranother and I from the outer ring II duringthe operation of bonding them to the rubber supporting body 13. Thisproblem can of course be solved by conventional methods of providing afixture in which there are means for gripping each individual pad andholding it in place but owing to the number of the pads such anarrangement is complicated and it is an object of the invention toprovide a method of manufacture which is relatively simple. v

According? to-*- the: invention the pads ['2 are formed as part of astructure shown in Figure 3 which consists of a phosphor bronze tube Itthe outside diameter of which is such as to corr'espond to the outercurveof 'theepa'ds; shown; in

Figures 1 and 2. The tube i's:-.macl'iined.circum ferentially withgrooves l4 and longitudinally with grooves l5 which sub-divide. itsouter. surface into rectangles corresponding with thepad's- The groovesare at least as deep as the thick ness of the pads but not deep enoughto cut through the thickness of the=tube lhLtheinternal diameter ofwhich is smaller than the" internal diameter of the finished liner shownin:Figures. l

and 2. The internal portion of the tube acts as temporary.holdingmeansfor supporting the pads II in their correct relation to.one another during subsequent operations.

The ring. [1,. which. may be. machined. so that itsexternal. diameter isslightly, oversize, and the. part. shown .inlFi'gure. 3 which. comprisesthe padsl-ZI and'the temporary holding. means constituted. by the inner.portion. of the tube. 16', are now taken and" introduced, concentricallywith one .another, intoa mould which isshown in Figure 4. The.mouldcomprises..a-ringshaped bottom plate thesellal'ves fits. into the.bottom plate IT as shown at 2.0".andtheyare notched out as shown at-21,22 in. their outer circumferences at the place where. they meet oneanother so that when the mould is disassembledand' the half portions IQ;of; the body are. to be taken. apartv from one another, a tool can beinserted into-therecesses 2!, 22 to prise them apart if.necessary. Aringshapedfeederplate- 23. fits. over the. top. of the body members IS.A packing ring 2 is interposedbetween-the feeder. plate i13'andthe upperedge of. the. core member l8. A. large annular groove 25 is machined,in. the upper part of a feeder. plate 23- and this groove is; connectedby aanumber of ductsZt-witlr the space between, the

tubetendthesupporting ring Ll. An-annular the feedercup 25 and. therubber'mix is forced through the ducts: 26finto: the space between thePhosphor bronze tube 16 and the outer steel supporting ring. I.l:.. Theparts are-left in this position; receiving heat fromztheplatens, untilthe mix' 'is-curedwhich wit-tr. aasuitable mix may 4 take half an hour.Thereafter the mould is removed from the press and taken apart, thebearing comprising the supporting ring II, the rubber body l3 and theinner tube 15 being removed intact. In this condition it bears theappearance shown in Figure 5 and is mounted in a lathe and the interiorof the tube [6 is machined out until the temporary supporting metalconstituted by the interior of the tube is removed and the supportingpads are freed from one another and remain embedded in the body ofsynthetic rubber :3 as shown in Figures 1 and 2. The ends being machinedsmooth and the exterior of the ring H machined concentric 'withthe'interior. of the bearing, the steps of theemethod'according to theinvention are completed.

Referring now to Figures 6 to 10, these show the manufacture of'a splitbearing such as might be-employedfor the big end of a connecting rod inan internal-combustion engine. The completed' bearingis-shown in Figures6 and '7 and comprises afi'anged outer supporting ring divided into twoparts 3i}, 3| and provided with flanges 32, 33. Within the ring30, 3|and bonded thereto .is a supporting body of vulcanised synthetic rubber343m which are embeddedan'd supported a number of separate Phosphor.bronze bearing pads. 36. Theseare separated from one another bylongitudinal spaces 39. which are filledwith rubber. The bearing pads 36are each divided into three sections, the division being effected bycircumferentially extending oil retaining grooves. 33; turned in theface of the bearing pads but not deep enough to cut. through. the metal.

In order to manufacture thisbearing, the pads 3.6. are. first formedby'turning the end of" a sleeve 31', shown inFigure 8' andthen slittingthe turned portion to separate the pads from one another. They remain,however; supported in their correct. relation to one another by theirconnectionat one end, to the unturned portion of the sleeve 31', whichacts as a temporary holding means. The outer supporting ring 39, 31 isturned to shape but in a single piece which is shownasthe piece 35" inFigures 9 and 10. The ring 35 and the holding means 3l'with the pads 36attached to it are assembled in a sectional mould shown inFigure 9' andconsistingcf'a ringshaped bottom plate 40, a split body 4| similar tothe body l9 already described in connection with Figure 4, an upper ring42 comprising a feeder cup 43. and a top plate id-having .an annularpiston. 45. to fit the feeder. cup. The feeder cup. is connected byducts 46 with the. space between the ring 35. and the pads 3.5 and whenthe mould is being assembled. uncured rubber mix is placed in the feedercup 43. The temporary holding member 31 and pads 36- are supported intheir proper relation with the mould by acore 41. which. fits theinterior of the. ringshaped bottom plate 40 and extends upwards throughthe body-4| into engagement with the upper ring 42 whichcontains-thefeeder cup.

Thus assembled the mould isinserted in a heated hydraulicpress, therubber is forced into the spaces between the parts of the bearing andthe whole bondedtogether and the rubber cured in situ as alreadydescribed in connection with Figure 4.

Thereafter the mould is. taken apart. and. the bearing appears as shownin Figure 10. The tubular temporary holding means is? mounted in. a:chuck, the bearing; turned internally. and

nuances g externally and parted offfrom A the temporary holding means.Thereafter is sawsineman portions sothat it appears in the completedform as shown inEigures Brandi. vIn making the pads 36, as showninrigures; it i'snot necessary to slit apart-the two pads which occ'npystheplace where the slit 49 appears diifl'des the bearing into two,-because theses pads are automatically divided fromone 'another'ih thefinal operation of sawing the bearing into two'pa'rts. j Referring now"to Figures 11 to 16, there-is T shown in Figures 11 and 12 an'oilsealing'ring. i This comprises a rubber'supportin'g bodyf5ll ingtheZrorm of Q a ring which supportsai number offin- Qtjerfnal bearing pads'5|"an'd11i"s supported by an external steel series of segment's'52which* con-,

l's'tit'ute'an outer ring; Thebeari'ng pads' 5 lia re sub-divided fromone another by rubber-filled spaces 53 and there are two rows of thepads 5| which are sub-divided by a rubber-filled circumferentiallyextending space 54. The spaces between the outer steel segments 52 arealso filled with rubber as shown at 55, Figure 11. The rub;- ber and themetal parts are bonded together and the whole forms a flexible sealingring which is capable of preventing the leakage of oil along a shaftfrom a bearing. The substantial radial depth of the rubber ring 50 makesthe segments 5| able to adapt themselves to any slight lack of roundnessin the shaft which passes through them and also ensures that the sealingring does not bear any substantial part of the load which comes on thebearing with which it is associated. Such sealing rings are manufacturedaccording to the present invention by first making a sleeve likeassembly which comprises a number of the rings in one piece and thenparting them off from one another.

Figure 13 of the drawings shows a tubular member 55 which acts as atemporary holding means for the pads 5|. the tubular holding member bytaking tubular stock of sufficient dimensions and machining slots 56along it lengthwise and circumferential slots 51 crossing the slots 56.It is to be noted that the circumferential slots 51 correspond in Thepads are formed on 6 and thereby vulcanisedand bonded" to: the parts.'es'ult, when' themould has been takenap'art, is compositetubularassembly comprising-the oui'ier' tu-bular'ring 58' and inner tube 55united together by a body of rubber 50 This can be bored out "internallyto remove the temporary "holding member 55 and' leave the pads 5| sup-"po'rtedonly by the rubber 50. '-Similarly, ma-

width to the circumferential division 54 between the pads 5|, as shownin Figure 12. The first slot 5'! is made at a distance from the end ofthe tubular member 55 which is half of the distance from the next slot51 for a reason which will presently appear. For the outer steelsegments 52 a tube is taken of a length equal to the tubular member 55of Figure 13 and of an internal di-.

amcter equal to the internal distance between the segments 52 measureddiametrically across the oil seal Figure 11. This sleeve is shown inFigure 14 at 58; it is grooved internally as shown at 55 to correspondwith the spaces 55 between the segments 52 and thus the segments areformed but are left attached to the exterior of the tube 58 whichconstitutes a temporary holding means.

The parts are introduced into a mould shown in Figure 15 comprising aring-shaped bottom plate a core member 6| fitting into the bottom plateand having a plug portion 62 which fits the interior of the tubularmember a split body portion 63; and upper ring-shaped portion 64containing a feeder cup 65, and a top plate 6'5 having an annular piston61 to fit the feeder cup. The feeder cup 65 is connected by ducts 68 tothe space between the tubular members 55, 58 and rubber from the feedercup is forced underheat and pressure as already described into thisspace 'cliiniiig' away the outer parto'f the tube58 willleave"theysegments-fli The member being then parted" along the chainlines 10; H, shown in Figure 16; three oil sealing rings such as are"shown" in Figures 11' and 12 are produced; It

will be 'appreciated that the dimensions of the parts need to be chosen'so asto allow for the lwfdthfofthe"partingofiltool and that the end-.iaces1"|2; '53 arealso' machined away to' give a 's'mo'othfinish' andto. make the dimensionsexact. In cases where it'is not possible" toformthe bearing surface elements as an integral part of a single memberwhich is subsequently machined away, it is possible to provide theelements with extensions which are supported in a holder and to machineaway the extensions after the moulding process.

The invention is not limited to the manufacture of'cylindrical bearingsor other cylindrical machine-parts of the kind described, as obviouslyconical bearings or thrust-washers or the like .of Figure 3, or thegrooves 59 of Figure 14, need not necessarily extend in a rectangularpattern .with the lines parallel to or at right angles to the axis ofthe tubular member as they could be machined in any other pattern, forexample a diamond pattern, if desired, according to the desired shape ofthe bearing pads or supporting elements which are to be produced in thefinished article. Moreover in the case of oil seals which require tohave the bearing surface elements on the outside instead of on theinside, or piston packings in which the bearing surface elements requireto be on the outside or in other like cases, the invention is equallyapplicable to the manufacture, the appropriate reversal of the shapedescribed being all that is necessary to produce the desired result.

In some cases machine parts produced as describedaccording to theinvention can be used for other purposes than bearings or oil seals, forexample as bushes or elements of couplings.

I claim:

1. A method of manufacture of a composite machine part wherein aplurality of bearing elements are embedded in rubber so as to besupported thereby while being spaced and separate from each other,consisting in first forming a tube of bearing material, machining aperipheral surface of the tube with intersecting grooves to divide thesurface into spaced sections corresponding to the intended bearingelements, forcing rubber under pressure in plastic condition intocontact with the grooved surface, maintaining the whole under heat andpressure until the rubber has become bonded to the grooved surface toproduce a unit, cooling the unit and machining away the other peripheralsurface of the tube to expose the intersecting grooves and separate thebearing elements from each other.

2. A method of manufacture of a composite machine part wherein aplurality of bearing elements are embedded in rubber so as to besupported thereby'while being spaced and separate surface of the tube todivide the surface into spaced sections'corresponding to the intendedbearing elements, assembling the tube in a mould with aco-axial secondtube around it and spaced fromits grooved peripheral surface, forcingrubher under pressure in plastic condition between thetwo tubes,maintaining the whole under heat and pressure until the rubber andsleeves are bonded together as a unit, and machining the insideperipheral surface of the inner sleeve to ex- .pose the grooves andseparate the bearing elements from each other. p I 3. A method of manufature of composite machine parts ,as claimed in claim 2, includingtheadditional step-after the machining operationof parting across the unitbetween the circumferential grooves to produce a plurality of compositemachine parts.

- v FRANK EDWARD BURGER.

REFERENCES CITED The following references are of record in the fileof'this patent:

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